samples/dragimag/dragimag.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dragimag.cpp
   3 // Purpose:     wxDragImage sample
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     28/2/2000
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx/wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #ifdef __BORLANDC__
  16 #pragma hdrstop
  17 #endif
  18
  19 #ifndef WX_PRECOMP
  20 #include "wx/wx.h"
  21 #endif
  22
  23 #include "wx/image.h"
  24
  25 // Under Windows, change this to 1
  26 // to use wxGenericDragImage
  27
  28 #define wxUSE_GENERIC_DRAGIMAGE 1
  29
  30 #if wxUSE_GENERIC_DRAGIMAGE
  31 #include "wx/generic/dragimgg.h"
  32 #define wxDragImage wxGenericDragImage
  33 #else
  34 #include "wx/dragimag.h"
  35 #endif
  36
  37 #include "dragimag.h"
  38
  39 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__) || defined(__WXMGL__) || defined(__WXX11__)
  40 #include "mondrian.xpm"
  41 #include "dragicon.xpm"
  42 #endif
  43
  44 // main program
  45
  46 IMPLEMENT_APP(MyApp)
  47
  48 // MyCanvas
  49
  50 IMPLEMENT_CLASS(MyCanvas, wxScrolledWindow)
  51
  52 BEGIN_EVENT_TABLE(MyCanvas, wxScrolledWindow)
  53   EVT_PAINT(MyCanvas::OnPaint)
  54   EVT_ERASE_BACKGROUND(MyCanvas::OnEraseBackground)
  55   EVT_MOUSE_EVENTS(MyCanvas::OnMouseEvent)
  56 END_EVENT_TABLE()
  57
  58 MyCanvas::MyCanvas( wxWindow *parent, wxWindowID id,
  59                     const wxPoint &pos, const wxSize &size )
  60         : wxScrolledWindow( parent, id, pos, size, wxSUNKEN_BORDER )
  61 {
  62     SetBackgroundColour(* wxWHITE);
  63
  64     SetCursor(wxCursor(wxCURSOR_ARROW));
  65
  66     m_dragMode = TEST_DRAG_NONE;
  67     m_draggedShape = (DragShape*) NULL;
  68     m_dragImage = (wxDragImage*) NULL;
  69     m_currentlyHighlighted = (DragShape*) NULL;
  70 }
  71
  72 MyCanvas::~MyCanvas()
  73 {
  74     ClearShapes();
  75
  76     if (m_dragImage)
  77         delete m_dragImage;
  78 }
  79
  80 void MyCanvas::OnPaint( wxPaintEvent &WXUNUSED(event) )
  81 {
  82     wxPaintDC dc( this );
  83     PrepareDC( dc );
  84
  85     DrawShapes(dc);
  86 }
  87
  88 void MyCanvas::OnEraseBackground(wxEraseEvent& event)
  89 {
  90     if (wxGetApp().GetBackgroundBitmap().Ok())
  91     {
  92         wxSize sz = GetClientSize();
  93         wxRect rect(0, 0, sz.x, sz.y);
  94
  95         if (event.GetDC())
  96         {
  97             wxGetApp().TileBitmap(rect, *(event.GetDC()), wxGetApp().GetBackgroundBitmap());
  98         }
  99         else
 100         {
 101             wxClientDC dc(this);
 102             wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 103         }
 104     }
 105     else
 106         event.Skip(); // The official way of doing it
 107 }
 108
 109 void MyCanvas::OnMouseEvent(wxMouseEvent& event)
 110 {
 111     if (event.LeftDown())
 112     {
 113         DragShape* shape = FindShape(event.GetPosition());
 114         if (shape)
 115         {
 116             // We tentatively start dragging, but wait for
 117             // mouse movement before dragging properly.
 118
 119             m_dragMode = TEST_DRAG_START;
 120             m_dragStartPos = event.GetPosition();
 121             m_draggedShape = shape;
 122         }
 123     }
 124     else if (event.LeftUp() && m_dragMode != TEST_DRAG_NONE)
 125     {
 126         // Finish dragging
 127
 128         m_dragMode = TEST_DRAG_NONE;
 129
 130         if (!m_draggedShape || !m_dragImage)
 131             return;
 132
 133         m_draggedShape->SetPosition(m_draggedShape->GetPosition()
 134                                     + event.GetPosition() - m_dragStartPos);
 135
 136         m_dragImage->Hide();
 137         m_dragImage->EndDrag();
 138         delete m_dragImage;
 139         m_dragImage = NULL;
 140
 141         wxClientDC dc(this);
 142         if (m_currentlyHighlighted)
 143         {
 144             m_currentlyHighlighted->Draw(dc);
 145         }
 146         m_draggedShape->SetShow(true);
 147         m_draggedShape->Draw(dc);
 148
 149         m_currentlyHighlighted = (DragShape*) NULL;
 150
 151         m_draggedShape = (DragShape*) NULL;
 152     }
 153     else if (event.Dragging() && m_dragMode != TEST_DRAG_NONE)
 154     {
 155         if (m_dragMode == TEST_DRAG_START)
 156         {
 157             // We will start dragging if we've moved beyond a couple of pixels
 158
 159             int tolerance = 2;
 160             int dx = abs(event.GetPosition().x - m_dragStartPos.x);
 161             int dy = abs(event.GetPosition().y - m_dragStartPos.y);
 162             if (dx <= tolerance && dy <= tolerance)
 163                 return;
 164
 165             // Start the drag.
 166             m_dragMode = TEST_DRAG_DRAGGING;
 167
 168             if (m_dragImage)
 169                 delete m_dragImage;
 170
 171             // Erase the dragged shape from the canvas
 172             m_draggedShape->SetShow(false);
 173             wxClientDC dc(this);
 174             EraseShape(m_draggedShape, dc);
 175             DrawShapes(dc);
 176
 177             switch (m_draggedShape->GetDragMethod())
 178             {
 179                 case SHAPE_DRAG_BITMAP:
 180                 {
 181                     m_dragImage = new wxDragImage(m_draggedShape->GetBitmap(), wxCursor(wxCURSOR_HAND));
 182                     break;
 183                 }
 184                 case SHAPE_DRAG_TEXT:
 185                 {
 186                     m_dragImage = new wxDragImage(wxString(_T("Dragging some test text")), wxCursor(wxCURSOR_HAND));
 187                     break;
 188                 }
 189                 case SHAPE_DRAG_ICON:
 190                 {
 191                     // Can anyone explain why this test is necessary,
 192                     // to prevent a gcc error?
 193 #if defined(__WXMOTIF__) || defined(__WXX11__)
 194                     wxIcon icon(dragicon_xpm);
 195 #else
 196                     wxIcon icon(wxICON(dragicon));
 197 #endif
 198
 199                     m_dragImage = new wxDragImage(icon, wxCursor(wxCURSOR_HAND));
 200                     break;
 201                 }
 202             }
 203
 204             bool fullScreen = wxGetApp().GetUseScreen();
 205
 206             // The offset between the top-left of the shape image and the current shape position
 207             wxPoint beginDragHotSpot = m_dragStartPos - m_draggedShape->GetPosition();
 208
 209             // Now we do this inside the implementation: always assume
 210             // coordinates relative to the capture window (client coordinates)
 211
 212             //if (fullScreen)
 213             //    beginDragHotSpot -= ClientToScreen(wxPoint(0, 0));
 214
 215             if (!m_dragImage->BeginDrag(beginDragHotSpot, this, fullScreen))
 216             {
 217                 delete m_dragImage;
 218                 m_dragImage = (wxDragImage*) NULL;
 219                 m_dragMode = TEST_DRAG_NONE;
 220
 221             } else
 222             {
 223                 m_dragImage->Move(event.GetPosition());
 224                 m_dragImage->Show();
 225             }
 226         }
 227         else if (m_dragMode == TEST_DRAG_DRAGGING)
 228         {
 229             // We're currently dragging. See if we're over another shape.
 230             DragShape* onShape = FindShape(event.GetPosition());
 231
 232             bool mustUnhighlightOld = false;
 233             bool mustHighlightNew = false;
 234
 235             if (m_currentlyHighlighted)
 236             {
 237                 if ((onShape == (DragShape*) NULL) || (m_currentlyHighlighted != onShape))
 238                     mustUnhighlightOld = true;
 239             }
 240
 241             if (onShape && (onShape != m_currentlyHighlighted) && onShape->IsShown())
 242                 mustHighlightNew = true;
 243
 244             if (mustUnhighlightOld || mustHighlightNew)
 245                 m_dragImage->Hide();
 246
 247             // Now with the drag image switched off, we can change the window contents.
 248
 249             if (mustUnhighlightOld)
 250             {
 251                 wxClientDC clientDC(this);
 252                 m_currentlyHighlighted->Draw(clientDC);
 253                 m_currentlyHighlighted = (DragShape*) NULL;
 254             }
 255             if (mustHighlightNew)
 256             {
 257                 wxClientDC clientDC(this);
 258                 m_currentlyHighlighted = onShape;
 259                 m_currentlyHighlighted->Draw(clientDC, wxINVERT);
 260             }
 261
 262             // Move and show the image again
 263             m_dragImage->Move(event.GetPosition());
 264
 265             if (mustUnhighlightOld || mustHighlightNew)
 266                  m_dragImage->Show();
 267         }
 268     }
 269 }
 270
 271 void MyCanvas::DrawShapes(wxDC& dc)
 272 {
 273     wxList::compatibility_iterator node = m_displayList.GetFirst();
 274     while (node)
 275     {
 276         DragShape* shape = (DragShape*) node->GetData();
 277         if (shape->IsShown())
 278           shape->Draw(dc);
 279         node = node->GetNext();
 280     }
 281 }
 282
 283 void MyCanvas::EraseShape(DragShape* shape, wxDC& dc)
 284 {
 285     wxSize sz = GetClientSize();
 286     wxRect rect(0, 0, sz.x, sz.y);
 287
 288     wxRect rect2(shape->GetRect());
 289     dc.SetClippingRegion(rect2.x, rect2.y, rect2.width, rect2.height);
 290
 291     wxGetApp().TileBitmap(rect, dc, wxGetApp().GetBackgroundBitmap());
 292
 293     dc.DestroyClippingRegion();
 294 }
 295
 296 void MyCanvas::ClearShapes()
 297 {
 298     wxList::compatibility_iterator node = m_displayList.GetFirst();
 299     while (node)
 300     {
 301         DragShape* shape = (DragShape*) node->GetData();
 302         delete shape;
 303         node = node->GetNext();
 304     }
 305     m_displayList.Clear();
 306 }
 307
 308 DragShape* MyCanvas::FindShape(const wxPoint& pt) const
 309 {
 310     wxList::compatibility_iterator node = m_displayList.GetFirst();
 311     while (node)
 312     {
 313         DragShape* shape = (DragShape*) node->GetData();
 314         if (shape->HitTest(pt))
 315             return shape;
 316         node = node->GetNext();
 317     }
 318     return (DragShape*) NULL;
 319 }
 320
 321 // MyFrame
 322 IMPLEMENT_DYNAMIC_CLASS( MyFrame, wxFrame )
 323
 324 BEGIN_EVENT_TABLE(MyFrame,wxFrame)
 325   EVT_MENU    (wxID_ABOUT, MyFrame::OnAbout)
 326   EVT_MENU    (wxID_EXIT,  MyFrame::OnQuit)
 327 END_EVENT_TABLE()
 328
 329 MyFrame::MyFrame()
 330 : wxFrame( (wxFrame *)NULL, wxID_ANY, _T("wxDragImage sample"),
 331           wxPoint(20,20), wxSize(470,360) )
 332 {
 333     wxMenu *file_menu = new wxMenu();
 334     file_menu->Append( wxID_ABOUT, _T("&About..."));
 335     file_menu->AppendCheckItem( TEST_USE_SCREEN, _T("&Use whole screen for dragging"), _T("Use whole screen"));
 336     file_menu->Append( wxID_EXIT, _T("E&xit"));
 337
 338     wxMenuBar *menu_bar = new wxMenuBar();
 339     menu_bar->Append(file_menu, _T("&File"));
 340
 341     SetIcon(wxICON(mondrian));
 342     SetMenuBar( menu_bar );
 343
 344 #if wxUSE_STATUSBAR
 345     CreateStatusBar(2);
 346     int widths[] = { -1, 100 };
 347     SetStatusWidths( 2, widths );
 348 #endif // wxUSE_STATUSBAR
 349
 350     m_canvas = new MyCanvas( this, wxID_ANY, wxPoint(0,0), wxSize(10,10) );
 351 }
 352
 353 void MyFrame::OnQuit( wxCommandEvent &WXUNUSED(event) )
 354 {
 355     Close( true );
 356 }
 357
 358 void MyFrame::OnAbout( wxCommandEvent &WXUNUSED(event) )
 359 {
 360     (void)wxMessageBox( _T("wxDragImage demo\n")
 361         _T("Julian Smart (c) 2000"),
 362         _T("About wxDragImage Demo"),
 363         wxICON_INFORMATION | wxOK );
 364 }
 365
 366 //-----------------------------------------------------------------------------
 367 // MyApp
 368 //-----------------------------------------------------------------------------
 369
 370 BEGIN_EVENT_TABLE(MyApp, wxApp)
 371     EVT_MENU(TEST_USE_SCREEN, MyApp::OnUseScreen)
 372 END_EVENT_TABLE()
 373
 374 MyApp::MyApp()
 375 {
 376     // Drag across whole screen
 377     m_useScreen = false;
 378 }
 379
 380 bool MyApp::OnInit()
 381 {
 382 #if wxUSE_LIBPNG
 383     wxImage::AddHandler( new wxPNGHandler );
 384 #endif
 385
 386     wxImage image;
 387     if (image.LoadFile(_T("backgrnd.png"), wxBITMAP_TYPE_PNG))
 388     {
 389         m_background = wxBitmap(image);
 390     }
 391
 392     MyFrame *frame = new MyFrame();
 393
 394     wxString rootName(_T("shape0"));
 395
 396     int i;
 397     for (i = 1; i < 4; i++)
 398     {
 399         wxString filename;
 400         filename.Printf(wxT("%s%d.png"), (const wxChar*)rootName, i);
 401     /* For some reason under wxX11, the 2nd LoadFile in this loop fails, with
 402        a BadMatch inside CreateFromImage (inside ConvertToBitmap). This happens even if you copy
 403        the first file over the second file. */
 404         if (image.LoadFile(filename, wxBITMAP_TYPE_PNG))
 405         {
 406             DragShape* newShape = new DragShape(wxBitmap(image));
 407             newShape->SetPosition(wxPoint(i*50, i*50));
 408
 409             if (i == 2)
 410                 newShape->SetDragMethod(SHAPE_DRAG_TEXT);
 411             else if (i == 3)
 412                 newShape->SetDragMethod(SHAPE_DRAG_ICON);
 413             else
 414                 newShape->SetDragMethod(SHAPE_DRAG_BITMAP);
 415             frame->GetCanvas()->GetDisplayList().Append(newShape);
 416         }
 417     }
 418
 419 #if 0
 420     // Under Motif or GTK, this demonstrates that
 421     // wxScreenDC only gets the root window content.
 422     // We need to be able to copy the overall content
 423     // for full-screen dragging to work.
 424     int w, h;
 425     wxDisplaySize(& w, & h);
 426     wxBitmap bitmap(w, h);
 427
 428     wxScreenDC dc;
 429     wxMemoryDC memDC;
 430     memDC.SelectObject(bitmap);
 431     memDC.Blit(0, 0, w, h, & dc, 0, 0);
 432     memDC.SelectObject(wxNullBitmap);
 433     m_background = bitmap;
 434 #endif
 435
 436     frame->Show( true );
 437
 438     return true;
 439 }
 440
 441 int MyApp::OnExit()
 442 {
 443     return 0;
 444 }
 445
 446 bool MyApp::TileBitmap(const wxRect& rect, wxDC& dc, wxBitmap& bitmap)
 447 {
 448     int w = bitmap.GetWidth();
 449     int h = bitmap.GetHeight();
 450
 451     int i, j;
 452     for (i = rect.x; i < rect.x + rect.width; i += w)
 453     {
 454         for (j = rect.y; j < rect.y + rect.height; j+= h)
 455             dc.DrawBitmap(bitmap, i, j);
 456     }
 457     return true;
 458 }
 459
 460 void MyApp::OnUseScreen(wxCommandEvent& WXUNUSED(event))
 461 {
 462     m_useScreen = !m_useScreen;
 463 }
 464
 465 // DragShape
 466
 467 DragShape::DragShape(const wxBitmap& bitmap)
 468 {
 469     m_bitmap = bitmap;
 470     m_pos.x = 0;
 471     m_pos.y = 0;
 472     m_dragMethod = SHAPE_DRAG_BITMAP;
 473     m_show = true;
 474 }
 475
 476 DragShape::~DragShape()
 477 {
 478 }
 479
 480 bool DragShape::HitTest(const wxPoint& pt) const
 481 {
 482     wxRect rect(GetRect());
 483     return rect.Inside(pt.x, pt.y);
 484 }
 485
 486 bool DragShape::Draw(wxDC& dc, int op)
 487 {
 488     if (m_bitmap.Ok())
 489     {
 490         wxMemoryDC memDC;
 491         memDC.SelectObject(m_bitmap);
 492
 493         dc.Blit(m_pos.x, m_pos.y, m_bitmap.GetWidth(), m_bitmap.GetHeight(),
 494             & memDC, 0, 0, op, true);
 495
 496         return true;
 497     }
 498     else
 499         return false;
 500 }
 501